1. Field of the Invention
This invention relates to a system and method for automatically orienting a spherical object, particularly a game ball, based on an existing “reference” pattern or indicium on the surface of the spherical object so that additional processing, e.g., printing, inspecting, etc. can take place on the spherical object at a target point that has a predetermined positional relationship with respect to the existing reference pattern or indicium.
2. Description of Prior Art
A growing segment of the golf ball industry is the manufacturing of balls customized with corporate logos, country club emblems, personal names, etc. These balls are usually produced by taking a finished golf ball and adding the custom printing at a predetermined location relative to the existing trade name or indicium printed on the ball. This is most commonly done by manually orienting the ball and placing it into a printing machine. Some of the problems with this method are: 1) it is labor intensive and therefore expensive, 2) it requires a significant training period for a person to become proficient at it, 3) a person is subject to fatigue and must take frequent breaks, 4) the process requires a great deal of repetitive motion, which can be source of injury, and 5) the accuracy is not as good as the system described herein.
U.S. Pat. No. 5,632,205 to Gordon (1997) describes a method of automatically orienting a game ball. This method uses a single station to perform the entire orientation on a single ball at a time. Two conical wheels are used to support the ball and rotate it around two orthogonal axes depending on whether the wheels are rotated in the same or opposite directions. The third axis of rotation is achieved by making two moves using the first two axes. The limitations of this method are: 1) operating rates are low, due to the fact that it performs the orientation on only one ball at a time, 2) the amount of time it takes to orient the ball can vary significantly depending on the initial orientation of the ball, making it difficult to synchronize the ball-orienting apparatus with the printing apparatus, which is usually designed to run at a fixed cycle rate, and 3) the area sensor camera photographs only a limited area of the surface of the ball at one time, therefore more images need to be acquired and, hence more time to process such images.
U.S. Pat. No. 5,611,723 to Mitoma (1997) describes another method of automatically orienting a golf ball in two dimensions for the purpose of removing molding burrs and flash from the equator of the ball. The Mitoma method describes a sequential arrangement that allows a different ball to be at each station of the orientation process simultaneously. The limitations of this system are that it requires six stations and three cameras to orient the ball in only two dimensions. The individual stations are mechanically and spatially complex because their orthogonal arrangement requires such stations to be considerably different from one another. Additionally, the conveyance arm that transports the balls from one station to the next adjacent station requires two degrees of freedom, one to lift and place the balls and another to transport them, therefore operating rates are low.